MCP

Stateless Streamable HTTP MCP endpoint.

Implementation details:

• Each POST /mcp request creates a fresh McpServer, handles the JSON-RPC exchange, then closes it.
• The transport runs with sessionIdGenerator: undefined and enableJsonResponse: true, so this server does not issue or require mcp-session-id headers.
• GET /mcp returns the info document and GET /.well-known/mcp.json returns the discovery document.
• Clients can use Accept: application/json with Content-Type: application/json.

Typical flow:

1. initialize
2. notifications/initialized
3. tools/list or tools/call

Initialize request example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "initialize",
  "params": {
    "protocolVersion": "2025-11-25",
    "capabilities": {},
    "clientInfo": {
      "name": "curl-example",
      "version": "1.0.0"
    }
  }
}

Initialize response example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "protocolVersion": "2025-11-25",
    "capabilities": {
      "tools": {
        "listChanged": true
      }
    },
    "serverInfo": {
      "name": "spl-private-payments-api",
      "version": "0.1.0"
    }
  }
}

Tool call request example:

{
  "jsonrpc": "2.0",
  "id": 3,
  "method": "tools/call",
  "params": {
    "name": "spl.deposit",
    "arguments": {
      "owner": "3rXKwQ1kpjBd5tdcco32qsvqUh1BnZjcYnS5kYrP7AYE",
      "amount": 1,
      "initIfMissing": true,
      "initAtasIfMissing": true,
      "initVaultIfMissing": true,
      "idempotent": true
    }
  }
}

POST /mcp

cURL

cURL

curl --request POST \
  --url https://payments.magicblock.app/mcp \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "initialize",
  "params": {
    "protocolVersion": "2025-11-25",
    "capabilities": {},
    "clientInfo": {
      "name": "curl-example",
      "version": "1.0.0"
    }
  }
}
'

import requests

url = "https://payments.magicblock.app/mcp"

payload = {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "initialize",
    "params": {
        "protocolVersion": "2025-11-25",
        "capabilities": {},
        "clientInfo": {
            "name": "curl-example",
            "version": "1.0.0"
        }
    }
}
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    jsonrpc: '2.0',
    id: 1,
    method: 'initialize',
    params: {
      protocolVersion: '2025-11-25',
      capabilities: {},
      clientInfo: {name: 'curl-example', version: '1.0.0'}
    }
  })
};

fetch('https://payments.magicblock.app/mcp', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://payments.magicblock.app/mcp",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'jsonrpc' => '2.0',
    'id' => 1,
    'method' => 'initialize',
    'params' => [
        'protocolVersion' => '2025-11-25',
        'capabilities' => [
                
        ],
        'clientInfo' => [
                'name' => 'curl-example',
                'version' => '1.0.0'
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://payments.magicblock.app/mcp"

	payload := strings.NewReader("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"initialize\",\n  \"params\": {\n    \"protocolVersion\": \"2025-11-25\",\n    \"capabilities\": {},\n    \"clientInfo\": {\n      \"name\": \"curl-example\",\n      \"version\": \"1.0.0\"\n    }\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://payments.magicblock.app/mcp")
  .header("Content-Type", "application/json")
  .body("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"initialize\",\n  \"params\": {\n    \"protocolVersion\": \"2025-11-25\",\n    \"capabilities\": {},\n    \"clientInfo\": {\n      \"name\": \"curl-example\",\n      \"version\": \"1.0.0\"\n    }\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://payments.magicblock.app/mcp")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"initialize\",\n  \"params\": {\n    \"protocolVersion\": \"2025-11-25\",\n    \"capabilities\": {},\n    \"clientInfo\": {\n      \"name\": \"curl-example\",\n      \"version\": \"1.0.0\"\n    }\n  }\n}"

response = http.request(request)
puts response.read_body

200

{
  "jsonrpc": "2.0",
  "id": 3,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "Built an unsigned SPL deposit transaction."
      }
    ],
    "structuredContent": {
      "kind": "deposit",
      "version": "legacy",
      "transactionBase64": "AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAIDKmcfsS5XfSOLaLlaBHJry50iH2Ufk2TMz4STC2fHzIcFKkerg3q2DD3Yn8TISmGeKoxSLz+BiP7iQ4pYqXYXsgu8D8C7R8ovdMQRLpSrE8+jxjTl3BfqywPNGiPNfnh8eS+smowIxqKDcCjw5liNXQkkCbBSDCBDFwtrgCKqoQ0DAgEBBAECAwQCAQEEAgIDBAIBAQQDAgME",
      "sendTo": "base",
      "recentBlockhash": "9A4VhP8M8fQZxP4h7rB6mP6eM8w2pJkYh7QdZk7V4r2x",
      "lastValidBlockHeight": 284512337,
      "instructionCount": 3,
      "requiredSigners": [
        "3rXKwQ1kpjBd5tdcco32qsvqUh1BnZjcYnS5kYrP7AYE"
      ],
      "validator": "MAS1Dt9qreoRMQ14YQuhg8UTZMMzDdKhmkZMECCzk57"
    }
  }
}

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32700,
    "message": "Parse error"
  },
  "id": null
}

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32000,
    "message": "Unsupported Media Type: Content-Type must be application/json"
  },
  "id": null
}

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32603,
    "message": "Internal server error"
  },
  "id": null
}

Body

application/json

MCP JSON-RPC request

jsonrpc · enum<string> · required

Available options: 2.0

method · string · required

id · string number

params · any

Response

200

application/json

MCP JSON-RPC response

jsonrpc · enum<string> · required

Available options: 2.0

id · string number

result · any

error · object

Show child attributes

{key} · any